Railway signaling system



Feb. 17, 1931. MQCANN ET'AL 1,793,184

RAILWAY S IGNALING SYSTEM Filed Feb. 15, 1930 Patented Feb. 17, 1931UNITED STATES PATENT OFFICE RONALD A. MCCANN AND CHARLES A. BROOKS,SWISSVALE, PENNSYLVANIA, AS- SIGNORS TO THE UNION SVIITCH 82; SIGNALCOMPANY, OF SN'ISSVALE, PENNSYL- VANIA, A CORPORATION OF PENNSYLVANIARAILWAY SIGNALING SYSTEM Application filed February 13, 1930. Serial No.428,144.

Our invention relates to railway signaling systems of the type involvinga switch and a signal governing traffic over such switch. One feature ofour invention is the provision of novel and improved means forautomatically causing said signal to give progressive indications as atrain passesprogressive distances beyond the signal.

We will describe one form of signaling system embodying our invention,and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form ofsystem embodying our invention.

Referring to the drawing, the reference characters 1 and 1 designate thetrack rails of a stretch of main track N, which rails are divided byinsulated joints 2 to form a plurality of successive track sections, ofwhich only two sections AB and B-C, are shown in the drawing. Located inthe section AB is a switch Q leading into a yard track Z. This yardtrack is provided with a track section DE, the end D of which is locatedbeyond the fouling point of the switch Q.

Traflic into the section AB, and therefore through the switch Q, isgoverned by a signal S. This signal comprises a main group of lamps V,and an auxiliary group of lamps W, each group comprising a green lampGr, a yellow lamp Y, and a red lamp R. The signal also is provided witha calling-on lamp Y The indications given by the signal S will beexplained during the explanation of the operation of the system as awhole.

The switch Q, is actuated to normal and reverse positions by a switchmechanism 4:, which in turn is controlled by a manually operable lever Phaving normal and reverse positions corresponding to those of theswitch.

' This lever comprises a pair of pole-changing contacts 5 and 6, wherebycurrent of normal polarity is supplied to the mechanism 4: fromterminals X and 0 when the lever is in the normal position, and currentof reverse polarity is supplied to the mechanism from these contactswhen the lever is in the reverse position. Lever P is also provided withadditional contacts 7 and 8, the functions of which will be explainedhereinafter.

The signal S is controlled in part by a manually operable lever P havinga middle position and a right-hand position, which positions we will forconvenience refer to as the normal and reverse positions. This lever isprovided with a contact 9 which is open when the lever is in the normalposition, and is closed when the lever is reversed. Associated with thelever P is a normally open push button 40 of the type which may beclosed by hand, but which immediately returns to the open position assoon as it is released. That is to say, this push button is of thenon-stick type.

Each track section is provided with a track circuit comprising a trackbattery 3, and a track relay designated by the reference character Twith a distinguishing exponent.

The reference character U designates a repeater relay, which iscontrolled in part by the track relays and in part by the switch lever Pl/Vhenthe switch lever is in the normal position, the circuit for relayU is from terminal X, through contact 7 of switch lever P contact 10 oftrack relay T contact 12 of track relay T and the winding of relay U toterminal 0. It foilows that with lever P in the normal position, relay Uwill be energized if and only if both track sections AB and BC for themain track N are unoccupied. iVhen lever P is reversed, thecircuit forrelay U is from terminal X, through contact 7, contact 11 of track relayT contact 12 of track relay T the wind ing of relay U to terminal 0. Itfollows that when lever P is reversed, relay U will be energized if andonly if track sections A-B and DE are unoccupied;

The reference character M designates a relay which is controlled in partby the track relays and by relay U, as well'as by the switch lever P Thecircuit for relay M is from terminal K, through contact 8 oflever Pcontact 13 of track relay T back contact 14: of relay U, and the windingof relay M to terminal 0. It follows that relay M will be energized whenand only when lever P is in the reverse position, track relay T isenergized, and track relay T is cleencrg izcd; that is, when and onlywhen lever P is reversed and section D-E is occupied by a train.

Signal S is directly controlled by a home relay H, a distant relay F, ayard relay J, and a calling-on relay K. This signal is also controlledin part by a circuit controller L opcratively connected with the switchQ, and con prising two normally closed contacts 17 and i9, and amn'n'lally open contact 18.

Ti e will assume that all the track sections A-l%, BC and D hl areunoccupied, that switch Q is in the normal position and that thedespatchcr desires to admit a. train moving toward the right intosection Al3. To do this he will. move the signal lever P to theright-hand or rererse position thereby energiaiug relay H, the circuitbeing from terminal X, through contact 9 on lever P contact of relay U,back contact 28 of yard relay J, back contact 32 of calling-on relay K,and the winding of relay H to terminal O. The circuit for the distantrelay F includes the normally closed contact 19 of the circuitcontroller L, as well as other controlling contacts to the right ofsection B-C, and for present purposes we will assume that this relay isenergized. Green lamp in group V of signal S will then be lighted by a.circuit which passes from terminal X, through the trout point of contact22 of relay H, front point. of contact of relay F. and lamp G toterminal 0. At the same time the lamp G in group VJ will be lighted by acircuit which includes the front point of contact 22 of relay H andnormally closed contact 11' of switch operated circuit controller L. nalS will then give the proceed indication. If the distant relay F isdeener ized, lamp c; of group V] will be ighted as before, but lamp Yinstead of lamp G in group V will be lighted, the circuit for lamp Yincluding the trout point of contact 22 of relay H, and the back pointof contact 23 of relay F. When the train enters section it B, it willdeenergizc track relay T and this in turn will decnerg ize relay U,thereby opening the circuit for relay H at contact 15 ct relay U. Thetwo red lamps R of signal. S will then be lighted by a. circuit whichincludes the back point of contact 22 of relay H and back contact 26 ofrelay J, as well as the two red lamps it in multiple. Signal S will thenindicate stop.

If switch reversed, and all three of the track sections are unoccupied,reversal of the signal lever P will result in lighting lamp G or lamp Yin group V, but lamp G in group V will remain extinguished be 'ause itscircuit *ill be open at switch operated contact 17.

Yo will now assume that switch Q isreversed, that section AB occupied bya train, and that the despatcher desires to admit a second train intothis section. Relay U will now be deenergized, because its circuit willbe opened at contact 12 of track relay T, and relay hi will bedccnergized because its circuit will be opened at contact 123 of thesame track relay. The dcspr. 'cher will then reverse the signal lever Pand will also close the push button l0. The calling-on relay K will thenecome energized by virtue ot a circuit which passes from terminal X,through contact 9 on the signal lever P push button etO, back point ofcontact 16 of relay M, back contact 21 of relay H, bacl: contact ofrelay .l, and the winding of callingpon relay K to terminal 0. Whenrelay ll becomes energized, lamp Y of signal S will become lighted byvirtue of a circuit which in cludes the trout point o't contact- 33 ofrelay K, and the signal will then give the calling-on indication. Wewill now assume that before the calling-on indication accepted by alollowing train, the train which occupies section A-B passes the pointD, thereby permitting track relay T to close and causing track relay Tto open. Relay U will continue to be deenergiaed because its circuitwill now be open at contact 11 of: track relay T, but relay M willbecome energized because its circuit will be closed at both contacts 13and 14. Relay J will then become energized by virtue of a circuit whichpasses from terminal X, through contact 9 on lever P contact 31 of relayK, front point of contact 16 (it relay hil, back contact 20 of relay H,and the winding of relay 3' to terminal 0. Relay 1';

is slow-releasing in characteristic. so that its front contact 31will-remain closed for a briei interval of time after the circuit forthis relay becomes opened at back contact oi lay J. During" thisintervalot time a stick circuit for relay J will become closed, whichcircuit passes from terminal X, through contact 9 of lever P frontcontact 27 oi? relay J, front point otcontact 16 of relay M, backcontact 20 of relay H, and the winding of relay J to terminal 0. It willbe observed that this transfer from relay K to relay J is entirelyautomatic, and does not require manual operation or the push button 40.With relay J energized, the yellow lamp Y of group V will be lighted byvirtue of a circuit which includes front contact 24 of this relay. LampY will also be lighted by virtue of a circuit which includes frontcontact 30 of relay J, and back contact of relay K. Signal to will thengive what is known as a yard indication, that is, it will indicate tothe following train that the switch Q is reversed. that section 1 -l3 isunoccupied, but that track section D-E of the yard trace: Z is occupied.

Signal S can be caused to give other indications than those specificallyreferred to, but such other indications have nothing to do with ourpresent invention, and, eonsetpiently,

it is notnecessary to explain them in detail.

Although we have herein shown and described only one form of signalingsystem embodying our invention, it is understood that various changesand modifications be made therein within the scope of the appendedclaims without departing from the spirit and scope of our invention.

Having thus described our invention. what we claim is: v

1. In combination, a stretch of railway track divided to form sectionsAB and BC provided with track relays T and T respectively, a switchleading from section AB into a yard track divided to form a section DEwhich is provided with a track relay T a signal governing trafficthrough said switch, a manual lever for said switch having normal andreverse positions, a manual lever for said signal having normal andreverse positions, a repeater relay U energized when said switch leveris normal provided track relays T and T are closed and energized whensaid switch lever is reverse provided track relays T and T are closed, arelay M energized when said switch lever is reversed provided trackrelay T is closed and relay U is open, a home relay and a yard relay anda slow-releasing calling-on relay for said signal, means for energizingsaid home relay when said signal lever is reversed provided said yardand calling-on relays are,

open and relay U is closed, a manually operable normally open pushbutton, means for energizing said calling-on relay when said signallever is reversed and said push button is closed provided said home andyard relays and relay M are all open, means operating when saidcalling-on relay is energized to energize said yard relay if relay Mcloses, means for subsequently keeping the yard relay energized as longas relay M remains closed and the signal lever remains reversed, andmeans for causing said signal to give a calling-on or a yard indicationaccording as said calling-011 or said yard relay is closed.

2. In combination, a section of railway track, a switch leading fromsaid section into a yard track, a manual lever for the control of saidswitch, a signal governing traiiic through said switch, a relay M, meansfor energizing said relay requiring that said switch lever be reversedand that said section be unoccupied and'that said yard track be occupiedby a train, a yard indication relay and a slow-releasing calling-onrelay, a signal lever and a normally open push button for controllingsaid signal, means operating when said signal lever is reversed and saidpush button is closed to energize said yard indication relay or saidcalling-on relay according as relay M is closed or open, means operatingif relay M closes while said calling-on relay is closed to energize saidyard indication relay without necessitating closing of said push button,and means for causing said signal to give a calling-on or a yardindication according as said calling-on or said yard relay is closed.

3. In combination, a stretch ofrailway track, a signal governing traflicthrough said stretch, a manual lever for the control of said signal, arelay M controlled by traific conditions in advance of said signal, ahome relay and a yard indication relay and a calling-on relay for saidsignal, a manually operable normally open push button, means forenergizing said calling-on relay when said signal lever is reversed andsaid push button is closed provided said home and yard relays and relayM are all open, means operating when said calling-on relay is energizedto energize said yard relay if relay M closes, means for subsequentlykeeping the yard relay energized as long as relay M remains closed andthe signal lever remains reversed, and means for causing said signal togive a calling-011 or a yard indication according as said calling-on orsaid yard relay is closed.

4. In combination, a stretch of railway track, a signal governingtraflic through said stretch, a manual lever for the control of saidsignal, a relay M controlled by traffic conditions in advance of saidsignal, a home relay and a yard indication relay and a calling-on relayfor said signal, a normally open push button for controlling saidsignal, means operating when said signal lever is reversed and said pushbutton is closed to energize said yard indication relay or saidcalling-on relay according as relay M is closed or open, means operatingif relay M closes while said callin on relay is closed to energize saidyard indication relay without necessitating closing of said push button,and means for causing said signal to give a calling-on or a yardindication according as said calling-on or said yard relay is closed.

In testimony whereof we afiix our signatures. v

RONALD A. MoCAN-N. CHARLES A. BROOKS.

